Many experts believe that atrophy, a partial or complete wasting away of tissue, and fibrosis, the growth of excess tissue, of the smooth muscle tissue in the body of the penis (cavernous smooth muscle) triggers problems with being able to maintain a firm erection. Poor ability to maintain an erection is often an early symptom of erectile dysfunction. Although the condition is called venous leak, the real problem is not with the veins but malfunction of the smooth muscle that surrounds the veins. The end result is difficulty with maintain a firm erection (losing an erection too quickly) that is now believe to be an early manifestation of atherosclerosis and vascular disease.


Once a complete sexual and medical history has been completed, appropriate laboratory studies should be conducted. In the initial evaluation of ED, sophisticated laboratory testing is rarely necessary. For example, serum testosterone (and sometimes prolactin) is typically only useful when the patient demonstrates hypogonadal features or testicular atrophy, or when clinical history is suggestive. Additional hormonal evaluation may include thyroid stimulating hormone in those with a clinical suspicion of hypothyroidism or appropriate diabetes screening in those presenting with a concern for impaired glucose metabolism. If the patient has not been evaluated with a lipid panel and hyperlipidemia is suspected, measurement and appropriate referral to internal medicine or cardiology is recommended. In most cases, a tentative diagnosis can be established with a complete sexual and medical history, physical examination, and limited or no laboratory testing.
Normal erectile function depends on the release of NO and endothelial-dependent vasodilation of the penile arteries. The ‘artery size’ hypothesis, first described by Dr Montorsi, offers an explanation why men are more likely to develop ED before a myocardial infacrtion. It is believed that atherosclerosis affects all vascular beds equally but smaller arteries are more likely to become occluded than larger arteries.31 32 The penile arteries are 1–2 mm while the coronary arteries are 3–4 mm. Thus, the same degree of endothelial dysfunction and atherosclerosis is more likely to occlude blood flow in the penile arteries compared with the coronary arteries. The penile arteries therefore serve as a sensitive indicator for subsequent CVD. This theory is supported by the fact that ED occurs approximately 3 years prior to cardiac symptoms in virtually all patients with chronic coronary syndrome whereas patients with acute coronary syndrome have a much lower prevalence of sexual dysfunction.32
ED may occur with or without other sexual dysfunction, including decreased libido (decreased interest in sexual activity), orgasmic dysfunction (troubles achieving an orgasm/climax), and ejaculatory dysfunction (problems with the fluid released during sex, including lack of ejaculation [anejaculation], small volume ejaculate, ejaculation that occurs too quickly [premature ejaculation], ejaculate that goes backward into the bladder [retrograde ejaculation] and pain with ejaculation).
ED usually has something physical behind it, particularly in older men. But psychological factors can be a factor in many cases of ED. Experts say stress, depression, poor self-esteem, and performance anxiety can short-circuit the process that leads to an erection. These factors can also make the problem worse in men whose ED stems from something physical.
Stanley A Brosman, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American Association for the Advancement of Science, American Association for Cancer Research, American College of Surgeons, American Medical Association, American Urological Association, Society for Basic Urologic Research, Society of Surgical Oncology, Society of Urologic Oncology, Western Section of the American Urological Association, Association of Clinical Research Professionals, American Society of Clinical Oncology, International Society of Urology, International Society of Urological Pathology
The physical side effects of chemotherapy are usually temporary and resolve within one to two weeks after stopping the chemotherapy. However, chemotherapy agents, such as Ciplatin or Vincristine, may interfere with the nerves that control erection leading to possible impotence. Make sure you discuss potential side effects of cancer chemotherapy with your doctor or healthcare provider.
Obesity and metabolic syndrome can cause changes in blood pressure, body composition, and cholesterol which may lead to ED. Other conditions that may contribute to erectile dysfunction include Parkinson’s, multiple sclerosis, Peyronie’s disease, sleep disorders, alcoholism, and drug abuse. Taking certain medications can also increase your risk for ED.
inability of the male to achieve or maintain an erection of sufficient rigidity to perform sexual intercourse successfully. An impotent man may produce sufficient numbers of normal spermatozoa; the condition is related to infertility only insofar as it prevents coitus with and impregnation of the female partner. Called also erectile dysfunction. adj., adj im´potent.

medicines called alpha-blockers such as Hytrin (terazosin
HCl), Flomax (tamsulosin HCl), Cardura (doxazosin
mesylate), Minipress (prazosin HCl), Uroxatral (alfuzosin HCl),
 Jalyn (dutasteride and tamsulosin HCl), or Rapaflo (silodosin).
Alpha-blockers are sometimes prescribed for prostate
problems or high blood pressure. In some patients, the use
of Sildenafil with alpha-blockers can lead to a drop in blood pressure or to fainting
Everything you need to know about chlamydia Chlamydia is the most common STI in the United States, yet most people do not experience obvious symptoms. Chlamydia affects men and women and can harm the reproductive systems, sometimes permanently. Find out about the causes and symptoms of chlamydia, as well as what the best treatments are and how to get screened. Read now

Size matters, so get slim and stay slim. A trim waistline is one good defense — a man with a 42-inch waist is 50% more likely to have ED than one with a 32-inch waist. Losing weight can help fight erectile dysfunction, so getting to a healthy weight and staying there is another good strategy for avoiding or fixing ED. Obesity raises risks for vascular disease and diabetes, two major causes of ED. And excess fat interferes with several hormones that may be part of the problem as well.
When other treatments haven’t helped, a penile implant may be the right solution. A penile implant is a medical device that is surgically placed into a penis to mimic the look and performance of a natural erection9. Implants are custom-fitted to your anatomy. Sensitivity and the ability to ejaculate aren’t typically affected either, so you’ll be able to have an orgasm normally (unless you have a medical condition that prevents this)7.
The FDA recommends that men follow general precautions before taking a medication for ED. Men who are taking medications that contain nitrates, such as nitroglycerin, should NOT use these medications. Taking nitrates with one of these medications can lower blood pressure too much. In addition, men who take tadalafil or vardenfil should use alpha blockers with care and only as instructed by their physician, as they could result in hypotension (abnormally low blood pressure). Experts recommend that men have a complete medical history and physical examination to determine the cause of ED. Men should tell their doctor about all the medications they are taking, including over-the-counter medications.

With the pumps, erections last until the user hits the deflate button, which Kohler says “doesn’t happen” accidentally. He adds that pump prostheses “are locker-room proof: Nobody can see that you have one.” (Obviously, this is not the case with the always-on malleable rod option.) Implanted pumps are reliable, experts say, with more than 90 percent of the devices working for 12 to 15 years. 
Prior to the introduction of PDE5i in 1998, intracavernosal vasoactive medications and penile implant surgery were the mainstays of treatment. Penile implant surgery involves placement of inflatable or malleable rods within the corpora cavernosa to provide rigidity for intercourse. Choice of which implant to place usually depends upon manual dexterity and function of the patient, patient anatomy, physician preference and surgical approach.

Penis pumps produce erections by drawing blood, via air suction, into the penis. The devices consist of a cylindrical tube, 12 to 18 inches long, connected by a small air hose to a hand pump (on many models this resembles the squeeze mechanism on a blood pressure monitor). Users place the tube over the penis then pump to produce an erection. They must then place an elastic band around the base of the penis to keep the blood there and maintain the erection.  

In some cases, nocturnal penile tumescence testing is performed to find out whether the man has erections while asleep. Healthy men usually have about four or five erections throughout the night. The man applies a device to the penis called a Rigiscan before going to bed at night, and the device can determine whether he has had erections. (If a man is able to have normal erections at night, this suggests a psychological cause for his impotence.)
The penis contains three cylinders, the two corpora cavernosa, which are on the top of the penis (see figure 1 below). These two cylinders are involved in erections. The third cylinder contains the urethra, the tube that the urine and ejaculate passes through, runs along the underside of the penis. The corpus spongiosum surrounds the urethra. Spongy tissue that has muscles, fibrous tissues, veins, and arteries within it makes up the corpora cavernosa. The inside of the corpora cavernosa is like a sponge, with potential spaces that can fill with blood and distend (known as sinusoids). A layer of tissue that is like Saran Wrap, called the tunica albuginea, surrounds the corpora. Veins located just under the tunica albuginea drain blood out of the penis.
Medication therapy is extremely effective in augmenting the quality of man’s erection such that he is able to have satisfactory intercourse. Indeed medications referred to as phospho-diesterase inhibitors such as Cialis, Viagra, Levitra and Stendra work in 65% of men suffering from erectile dysfunction. Cialis is currently the preferred drug since it is the only one that may be taking on a full stomach and lasts for 36 hours. This favors a more romantic and natural sexual interaction. Planning kills the mood!
Chronic stress dumps adrenaline in your system multiple times a day. And that can lead to high blood pressure, heart disease, obesity, and diabetes. Chronic stress is like red-lining your car all day long. When you drive 100 mph all the time, something is going to break down. A high-stress environment can actually change the way your brain sends messages to your body. Dumping too much adrenaline into your bloodstream can affect blood flow and severely limit your ability to achieve and maintain an erection.
Oral medicines: The best known ED medications are the Big Three: Viagra (sildenafil citrate, made by Pfizer, Inc.), Levitra (vardenafil HCl, made by Bayer and GlaxoSmithKline), and Cialis (tadalafil, made by Eli Lilly). The three are chemically very similar, and all have proven very effective. Because they are effective, convenient, and relatively inexpensive (about nine dollars per pill), these medicines have become the treatment of choice for most men experiencing ED.
Many factors can contribute to sexual dysfunction in older men, including physical and psychological conditions, comorbidities and the medications used to treat them. Aspects of an ageing man’s lifestyle and behaviour and androgen deficiency, most often decreasing testosterone levels, may affect sexual function as well. A study of men between the ages of 30 and 79 years showed that 24% had testosterone levels below 300 ng/dL and 5.6% had symptomatic androgen deficiency.2

Nearly every primary care physician, internist and geriatrician now understand that many older men retain an interest in sexual activity as they age. Some primary care physicians think that sexual potency in older men is the norm, and that if it is lacking, it is ‘all in the head.’ This viewpoint has not been supported by current literature. The Massachusetts Male Aging Study (MMAS) found that 52% of men between 40 and 70 years old reported having some form of erectile dysfunction (ED).1 The reality is that ED is a natural part of ageing and that the prevalence increases with age. In the MMAS, they found that roughly 50% of men at 50 years old, 60% of men at 60 years old and 70% of men at 70 years old had ED. Thus, nearly all men who live long enough should develop ED. The myths that surround the problems of impotence or ED confound the attempts of patients to receive treatment and the attempts of physicians to help them.1

A larger national study, the National Health and Social Life Survey, looked at sexual function in men and women.4 This study surveyed 1,410 men aged 18 to 59 and also documented an increase in ED with age. Additionally, the study found a decrease in sexual desire with increasing age. Men in the oldest cohort (50 to 59) were more than 3 times as likely to experience erection problems and to report low sexual desire compared with men 18 to 29. Experience of sexual dysfunction was more likely among men in poor physical and emotional health. The study also concluded that sexual dysfunction is an important public health concern and that emotional issues are likely to contribute to the experience sexual dysfunction.
In patients with low testosterone, testosterone treatment can improve libido and erectile dysfunction, but many men still may need additional oral medications such as sildenafil, vardenafil, or tadalafil. Some studies suggest that men with ED and low testosterone may respond better to PDE5 inhibitors when given testosterone therapy; however, this is controversial.
Many common medications for treating hypertension, depression, and high blood lipids (high cholesterol) can contribute to erectile dysfunction (see above). Treatment of hypertension is an example. There are many different types (classes) of medications for high blood pressure; these include beta-blockers, calcium channel blockers, diuretics (medications that increase urine volume), angiotensin converting enzyme inhibitors (ACE inhibitors), and angiotensin receptor blockers (ARBs). Patients may use these medications alone or in combination to control blood pressure. Some of these medications can cause troubles with erections. For example, Inderal (a beta-blocker) and hydrochlorothiazide (a diuretic) cause erectile dysfunction, while calcium channel blockers and ACE inhibitors do not seem to affect erectile function. On the other hand, other medications (such as angiotensin receptor blockers [ARB] including losartan [Cozaar] and valsartan [Diovan]) may actually help with erections. Therefore, if possible, you may benefit from changing your medications, but this requires approval by your prescribing health care provider.
The somatosensory pathways for erections originate in the penile skin, glans and urethra. Glans afferent sensory free nerve endings are 10-fold more than their corpuscular receptors, and are derived from Aδ and unmyelinated C fibers. The nerve endings coalesce to form the dorsal penile nerve along with other sensory nerve fibers. Through the pudendal nerve they enter the S2-4 nerve roots to terminate on spinal neurons and interneurons. The dorsal nerve is not purely somatic, however. Nerve bundles within the dorsal nerve contain nitric oxide (NO) synthase, found typically in autonomic nerves, and stimulation of the sympathetic chain can leak to evoked potentials from the dorsal nerve and vice versa (10-12).

There are hundreds of medications that have the side effect of ED and/or decreased libido. Examples of drugs implicated as a cause of ED include hydrochlorothiazides and beta-blocking agents. Medications used to treat depression, particularly the SSRIs such as citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac, Prozac Weekly, Sarafem), fluvoxamine (Luvox, Luvox CR), paroxetine (Paxil, Paxil CR, Pexeva) and sertraline (Zoloft), may also contribute to ED.9 Bupropion (Wellbutrin) which has a predominant effect on blocking the reuptake of dopamine is an antidepressant with lower incidence of ED.10 The side effects of 5ARIs occurring in fewer than 5% of patients can include gynaecomastia, ED, loss of libido and ejaculatory dysfunction.11
Erections are initiated and maintained via integration of afferent inputs in the supra sacral regions of the central nervous system. Regions of the brain cited to have key roles in the integration of signals include the medial amygdala, MPOA, periaqueductal gray matter, paraventricular nucleus (PVN), and ventral tegmentum among others (16). Studies in animal models, particularly in rats, have been paramount in identifying these key areas of signal integration and control. Electrostimulation of the MPOA, PVN and hippocampus lead to erection and lesions in these areas may prevent erection (17). Marson et al. injected labeled pseudorabies virus into rat corpora cavernosa and traced them to neurons in the spinal cord, brain stem and hypothalamus (18). Stimulation of the rat dorsal nerve led to increased firing in the MPOA not found elsewhere (19). Axonal tracing in animals have shows direct projections from the hypothalamus to the lumbosacral autonomic erection centers. Oxytocin and vasopressin have been identified as central neurotransmitters within the hypothalamic nuclei and may have a role in penile erection (17). These signaling studies identifying key areas of erectile response integration may explain how ED is associated with cerebrovascular accident (CVA), Parkinson’s, epilepsy and MS.
Hormone deficiency or hypogonadism, whether primary or secondary, has been thought to impact erectile function. Approximately a third of men in the European Male Aging Study demonstrated low testosterone, suggesting that hypogonadism is overrepresented among men with ED.11 Hormone deficiency, however, is less frequently the cause of ED than diabetes or vascular disease. Many entities with a strong relationship to ED also diminish bioavailable testosterone, including obesity, diabetes, and opioid use. Other hormones involved in testosterone metabolism or availability, like thyroid stimulating hormone and gonadotropins, also may impact erectile quality, presumably through regulating bioavailable testosterone. Understanding the relationship between testosterone and ED has been impaired by a lack of standardized measurement of this hormone and the cyclic nature of its release and consumption.

ED can also occur among younger men. A 2013 study found that one in four men seeking their first treatment for ED were under the age of 40. The researchers found a stronger correlation between smoking and illicit drug use and ED in men under 40 than among older men. That suggests that lifestyle choices may be a main contributing factor for ED in younger men.

Like all diabetic complications, ED can occur even when you have followed your doctor’s advice and carefully managed your diabetes. Also like all diabetes complications, ED is less likely to occur with good blood sugar control. Poorly controlled diabetes and high cholesterol increase the chances of vascular complications, which may lead to ED or other circulatory problems. In addition, regular smoking and alcohol use can contribute to ED.


In some cases, ED can be a warning sign of more serious disease. One study suggests ED is a strong predictor of heart attack, stroke, and death from cardiovascular disease. The researchers say all men diagnosed with ED should be evaluated for cardiovascular disease. This does not mean every man with ED will develop heart disease, or that every man with heart disease has ED, but patients should be aware of the link.
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